Investigation of Effect of Chemical Etching and Temperature on Optical Properties of Porous Silicon Layer

2011 ◽  
Vol 311-313 ◽  
pp. 1773-1778
Author(s):  
Yong Fu Long ◽  
Chun Mei Yao ◽  
Li Yun Lei ◽  
Wei Wen Hu ◽  
Bin Fang Cao ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Porous Silicon ◽  
Optical Thickness ◽  
Chemical Etching ◽  
Etching Rate ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
Photoluminescence Spectra

The paper investigated the effect of chemical etching and temperature on the optical properties and microstructures of porous silicon layer fabricated by the pulse electrochemically etching by means of the reflectance spectroscopy and photoluminescence spectroscopy. The relationship between the optical thickness (nd) and refractive index n of porous silicon layer and the chemical etching time and temperature has been detailedly studied. With increasing the chemical etching times, the reflectance spectra exhibit the more intense interference oscillations, which mean the uniformity and interface smoothness of porous silicon layers become better, meanwhile, results in decreasing the optical thickness and refractive index, indicating a higher porosity. Moreover, the intensity of photoluminescence spectra increases, and the envelope curves of photoluminescence spectra exhibit a trend of red-shift, which implied the average diameter of silicon nanocrystallite became larger. The chemical etching rate of the optical thickness intensely increases with the chemical etching temperature.

Morphological and Optical Characterization of Gold Nanoparticles Decorated Porous Silicon

2019 ◽  
Vol 19 (6) ◽  
pp. 3604-3609
Author(s):  
F Severiano ◽  
V. L Gayou ◽  
G García ◽  
J. A Luna-López ◽  
H. Martínez Gutiérrez ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Porous Silicon ◽  
Chemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Sem Analysis ◽  
Etching Time ◽  
Si Nanocrystals ◽  
Average Size ◽  
20 Nm

In this article, physical characteristics of porous silicon (PS) obtained by electro chemical etching using HAuCl4 in the electrolyte are described. The morphological and optical features of PS decorated with gold-nanoparticles (AuNPs) were analyzed in function of the chemical etching time. The insertion of AuNPs inside the PS were performed simultaneously with the formation of the porous silicon layer. Scanning electron microscopy (SEM) analysis showed the formation and incorporation of AuNPs with an average size of 20 nm in the PS structure, which has a pore size of 1.5 μm. Also, it was possible to observe the loss of Si in function of the etching time. Photoluminescence spectroscopy analysis shows a decreasing of the PL intensity, which can be related to the presence of oxygen in the samples. Raman spectroscopy was used to estimate the size of the Si nanocrystals in the PS structure, which suffers a reduction in size due to the presence of HAuCl4 in the electrolyte.

Effect of Etching Time on Electrical and Optical Properties of Porous Silicon

2013 ◽  
Vol 667 ◽  
pp. 397-401
Author(s):  
S.F.M. Yusop ◽  
N. Azaman ◽  
Hartini Ahmad Rafaie ◽  
S. Amizam ◽  
Saifollah Abdullah ◽  
...  
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Constant Current ◽  
Voltage Source ◽  
Etching Time ◽  
Constant Current Density ◽  
Wafer Substrate

The characterized on porous silicon layer by using photoluminescence (PL) and I-V measurement (I-V) has been done. Porous silicon was formed by electrochemical etching on (100) p-type Si wafer substrate with the constant current density (20mA/cm2) and variable the etching time. The samples ware prepared under various etching time and properties of porous silicon depend on an etching time. Porous silicon has been used in humidity sensors to detect humidity through changes of its electrical properties. The samples of porous silicon were characterized by using Photoluminescence Spectroscopy (PL) that used to characterize optical properties while I-V Measurement (I-V) used to characterize porous silicon junction properties using a linear voltage source. The result shows PL intensity is increase while the wavelength is decrease for etching time of PSi is longer. For the I-V measurement result shows the etching time affect the resistance of sample due to its porosity.

scholarly journals Effect of photo chemical etching and electro chemical etching on the topography of porous silicon wafers surfaces

2019 ◽  
Vol 24 (4) ◽  
pp. 52
Author(s):  
Amjad Hussein Jassem
Keyword(s):  
Porous Silicon ◽  
Layer Thickness ◽  
Porous Layer ◽  
Chemical Etching ◽  
Chemical Method ◽  
Pore Diameter ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time

In This research we study the effect of photo chemical etching and electrochemical etching on topography of porous silicon surfaces, the results showed that photo chemical etching produced roughness silicon layer which can have thickness be less of porous silicon layer which is produced by electro chemical etching When all the wafers have same etching time  and hydrofluoric solution (HF) concentration, the wafers have same resistance (10 Ω.cm). Also the results showed the roughness of porous silicon layers produced  by  electro chemical method which is bigger than the roughness of porous silicon layers produced by photo chemical method and the results of roughness of porous silicon layers, Pore diameter and porous layer thickness were produced by electro chemical method (1.55(µm) ((0.99(µm)) and ((1.21(µm) respectively), the results of roughness of porous silicon layers, Pore diameter and porous layer thickness were produced by photo chemical method 0.63)) nm -1.55)) (µm) ),so the (84.9 (nm)- and (3.94(nm) respectively . This is reinforces because of using the electro chemical to etching the wafer surf ace of bulk silicon and changing it to roughness silicon surface  be share in success of many practicalities.   http://dx.doi.org/10.25130/tjps.24.2019.072

Sensing mechanism analysis on one-dimensional photonic crystal with air slot-porous silicon-air slot F–P cavity

2019 ◽  
Vol 33 (13) ◽  
pp. 1950159 ◽  
Author(s):  
Ying Chen ◽  
Xinbei Gao ◽  
Pei Luo ◽  
Yangmei Xu ◽  
Jinggang Cao ◽  
...  
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Porous Silicon ◽  
Structural Parameters ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Resonant Peak ◽  
Mechanism Analysis ◽  
Q Value ◽  
Quality Factor Q

Based on the evanescent wave resonance, a photonic crystal sensing structure with air slot-porous silicon-air slot Fabry–Perot cavity (F–P cavity) is proposed. Taking the F–P cavity as the sensing unit, when the gas to be detected is filled into the sensing unit, the refractive index of the air slot will be changed and the refractive index of the porous silicon layer will also be varied, both of which will shift the resonant peak and greatly increase the sensitivity of the sensor. By adjusting the structural parameters, the quality factor (Q value) can be optimized. A model for the relationship between the resonant wavelength and the refractive index of the detected organic gas was established, and the refractive index sensing performance was analyzed. The results show that the Q value of the structure can attain to 12312.2 and the sensitivity is about 8661.708 nm/RIU, which can provide effective theoretical reference and technical guidance for organic gas detection with low concentration.

Effects of Electrochemical Etching Time on the Performance of Porous Silicon Solar Cells on Crystalline n-Type (100) and (111)

2017 ◽  
Vol 46 ◽  
pp. 45-56 ◽  
Author(s):  
Khalid Omar ◽  
Khaldun A. Salman
Keyword(s):  
Solar Cells ◽  
Porous Silicon ◽  
Crystalline Silicon ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Silicon Solar Cells ◽  
Etching Time ◽  
Crystalline Silicon Solar Cells ◽  
Coating Layers

Electrochemical etching was carried out to produce porous silicon based on crystalline silicon n-type (100) and (111) wafers. Etching times of 10, 20, and 30 min were applied. Porous silicon layer was used as anti-reflection coating on crystalline silicon solar cells. The optimal etching time is 20 min for preparing porous silicon layers based on crystalline silicon n-type (100) and (111) wafers. Nanopores with high porosity were produced on the porous silicon layer based on crystalline silicon n-type (100) and (111) wafers with average diameters of 5.7 and 5.8 nm, respectively. Average crystallite sizes for the porous silicon layer based on crystalline silicon n-type (100) and (111) wafers were 20.57 and 17.45 nm at 20 and 30 min, respectively, due to the increase in broadening of the full width at half maximum. Photoluminescence peaks for porous silicon layers based on crystalline silicon n-type (100) and (111) wafers increased with growing porosity and a great blue shift in luminescence. The minimum effective coefficient of reflection was obtained from porous silicon layers based on the crystalline silicon n-type (100) wafer compared with n-type (111) wafer and as-grown at different etching times. Porous silicon layers based on the crystalline silicon n-type (100) wafer at 20 min etching time exhibited excellent light trapping at wavelengths ranging from 400 to 1000 nm. Thus, fabricated crystalline silicon solar cells based on porous silicon (100) anti-reflection coating layers achieved the highest efficiency at 15.50% compared to porous silicon (111) anti-reflection coating layers. The efficiency is characterized applying I-V characterization system under 100 mW/cm2 illumination conditions.

Controllability And Homogeneity Of Optical Properties Of Thin Porous Silicon Films

1997 ◽  
Vol 486 ◽  
Author(s):  
S. Uehara ◽  
T. Kubo ◽  
S. Ogata ◽  
T. Sato ◽  
J. Hosono ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Porous Silicon ◽  
Optical Thickness ◽  
Wavelength Dependence ◽  
Effective Medium Approximation ◽  
Electrode Position ◽  
High Porosity ◽  
Optical Homogeneity ◽  
Reflection Spectroscopy

AbstractReflection spectroscopy was applied to evaluate the optical homogeneity and the refractive index of thin porous silicon (PS) layer. Variation in PS layer optical thickness was evaluated by measuring and mapping the reflectance over the surface area. For the circular anodization area of 17 mm diameter, the measured variation was less than 5 % on an area of 11 mm diameter. The anodization electrode position was found to have little influence on the homogeneity. A method to derive refractive index from a reflection spectrum is studied. The wavelength dependence of PS index measured by the method showed fair coincidence with the calculation based on effective medium approximation. In the two layer PS formation, optical thickness was found to change whether high porosity or low porosity layer is formed first.

scholarly journals Modification of Surface Properties of Silicon Wafers by Laser-Assisted Electrochemical Etching

2018 ◽  
Vol 80 ◽  
pp. 30-39
Author(s):  
Hasan A Hadi
Keyword(s):  
Porous Silicon ◽  
Optical Microscopy ◽  
Surface Topography ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Diffraction Peak ◽  
Etching Time ◽  
Layer Formation ◽  
Xrd Patterns

In this paper, the structural properties of porous silicon layer PSL were reported. Photo-assisted (laser) electrochemical etching PECE technique used to fabrication PSL from n-type wafer silicon as a function of etching time. Optical microscopy OM image is confirmed that the surface topography of porous silicon layer formation was a mud-like structure. The porosity and thickness have been determined gravimetrically are varied from 61% to 82% and 7.2 µm to 9.4µm respectively. The XRD patterns show that one diffraction peak for all PSL through anodization duration and it is assigned to the (400) plane and data confirmed the porous silicon PS was nanocrystalline.

scholarly journals The Effect of Etching Time On Structural Properties of Porous Quaternary AlInGaN Thin Films

2021 ◽  
Vol 19 (50) ◽  
pp. 77-83
Author(s):  
Ghasaq Ali Tomaa ◽  
Alaa Jabbar Ghazai
Keyword(s):  
Porous Silicon ◽  
Crystal Size ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
Etching Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Homogeneous Pattern

Using photo electrochemical etching technique (PEC), porous silicon (PS) layers were produced on n-type silicon (Si) wafers to generate porous silicon for n-type with an orientation of (111) The results of etching time were investigated at: (5,10,15 min). X-ray diffraction experiments revealed differences between the surface of the sample sheet and the synthesized porous silicon. The largest crystal size is (30 nm) and the lowest crystal size is (28.6 nm) The analysis of Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM) were used to research the morphology of porous silicon layer. As etching time increased, AFM findings showed that root mean square (RMS) of roughness and porous silicon grain size decreased and FESEM showed a homogeneous pattern and verified the formation of uniform porous silicon.

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